If you cannot make these left eye / right eye images merge, it often helps to fashion a pair of binoculars (without lenses), so you are looking at the screen through parallel tubes, with each eye just seeing one image. Alternatively, you can hold your hand, fingers extended, in front of your face, in such a way that each eye sees only one of the two images. Then it often is possible to make the two images blend, to make 3-D.
